1. Field of the Invention
The present invention is for a brush wear adjustment system and method, and in particular relates to a brush wear adjustment system for use in a street sweeping vehicle.
2. Description of the Prior Art
Rotary brushes utilized in street sweepers generally are mounted to the chassis of a truck or other suitable vehicle or structure. Normal wear and tear of a rotary brush during the sweeping mode results in worn rotary brush bristles the lengths of which are continually reduced due to abrasive qualities of the roadway with normal usage. The axle of the rotary brush is often secured between opposing pivot arms which gravitationally and automatically adjust in vertical fashion about pivot points to suitably contact the roadway and to compensate for the reduction in bristle length. As the bristle length is reduced, efficiency and effectiveness of the sweeping operation is increasingly degraded. Effective sweeping is predicated partially on the speed of the bristle tip, and is also predicted partially by the pressure of the bristles exerted downwardly to meet the roadway. A new rotary brush has long bristles which produces the highest bristle tip speed, and a well worn rotary brush has short bristles which produces a significantly slower and less effective bristle tip speed for the same rotary brush rate of rotation, thereby resulting in poorer and less effective sweeping. As the bristles wear, the rotary brush exhibits less control by gravitational downward force, thereby causing a lighter impingement with the roadway. Truck sweeper operators have lacked displays indicating brush wear which can be conveniently read in the control cab of a street sweeper. What is needed is a system which compensates for the degraded sweeping effectiveness and efficiency caused by continually shortening of the bristles of a rotary brush and which also displays brush wear. Such a system to provide consistent sweeping performance by increasing RPM of the rotary broom and/or adjusting the down pressure of the rotary broom is provided for by the present invention and method.